package com.util;

import com.drew.imaging.ImageMetadataReader;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifDirectory;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

public class ImageUtil {

    public static BufferedImage rotaImage(String path) throws IOException {
        try{
//            System.out.println(path);
            int angle = getImgRotateAngle(new File(path)) ;
//            System.out.println(angle);
            if (angle == 0) {
                return ImageIO.read(new File(path));
            }else {
                BufferedImage img = Rotate(ImageIO.read(new File(path)) , angle) ;
                return img ;
            }

        }catch (Exception e) {
            e.printStackTrace();
            System.out.println("报错了");
        }
        return ImageIO.read(new File(path));
    }

    public static BufferedImage rotaImage(File path){
        try{
            System.out.println(path);
            int angle = getImgRotateAngle(path) ;
            System.out.println(angle);
            BufferedImage img = Rotate(ImageIO.read(path) , angle) ;
            return img ;
        }catch (Exception e) {
            e.printStackTrace();
            System.out.println("报错了");
        }
        return null ;
    }

    public static BufferedImage Rotate(Image src, int angel) {
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        // 旋转后图片
        Rectangle rect_des = CalcRotatedSize(new Rectangle(new Dimension(
                src_width, src_height)), angel);
        BufferedImage res = null;
        res = new BufferedImage(rect_des.width, rect_des.height,
                BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = res.createGraphics();
        // 转换
        g2.translate((rect_des.width - src_width) / 2,
                (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

        g2.drawImage(src, null, null);
        return res;
    }

    /**
     * 旋转后的图片
     * @param src   被旋转的图片
     * @param angel 旋转角度
     * @return 旋转后的图片
     */
    public static Rectangle CalcRotatedSize(Rectangle src, int angel) {
        // 如果旋转的角度大于90度做相应的转换
        if (angel >= 90) {
            if (angel / 90 % 2 == 1) {
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }

        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);

        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha
                - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new Rectangle(new Dimension(des_width, des_height));
    }

    /**
     * 获得图片调整角度
     * make by dongxh 2017年11月1日下午3:40:20
     * @return
     */
    private static Integer getImgRotateAngle(File file){
        Integer angel = 0;
        Metadata metadata = null;
        try{
            if(!file.exists()){
                return angel;
            }
            metadata = ImageMetadataReader.readMetadata(file) ;
            Directory directory = metadata.getDirectory(ExifDirectory.class);
            if(directory != null && directory.containsTag(ExifDirectory.TAG_ORIENTATION)){
                int orientation = directory.getInt(ExifDirectory.TAG_ORIENTATION);
                // 原图片的方向信息
                if(6 == orientation || 5 == orientation){
                    //6旋转90
                    angel = 90;
                }else if( 3 == orientation){
                    //3旋转180
                    angel = 180;
                }else if( 8 == orientation){
                    //8旋转90
                    angel = 270;
                }
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        return angel;
    }
}
